Service providers provide a variety of network-based services to subscribing customers. For example, an Internet Service Provider (ISP) provides access to the Internet, thereby allowing a customer to browse the World Wide Web (WWW), communicate via electronic mail (email), exchange electronic documents, and access remote network resources. Some service providers provide other types of services, such as Internet Protocol (IP) telephony, video conferencing, multimedia streaming, Voice on Demand (VoD), Video-Surveillance, Voice over Internet Protocol (VoIP) communications, IP-TV, and gaming networks.
Some service providers execute service contracts with customers and guarantee a certain level of Quality of Service (QoS). One manner in which service providers currently provide different QoS guarantees is by monitoring network traffic and applying policies based characteristics of the traffic, e.g., packet header information. For example, a service provider may select and apply specific QoS policies to network traffic based on the particular port numbers specified in packet header information of the traffic. Because port numbers are generally associated with certain types of services, this scheme allows the service providers to distinguish between certain types of traffic. For example, a service provider may prioritize Hyper Text Transfer Protocol (HTTP) traffic, which is associated with port 80, higher than File Transfer Protocol (FTP) traffic, which is associated with port 20.
However, this type of prioritization scheme is relatively inflexible, and is generally inapplicable to many types of services due to the fact that many services dynamically assign port numbers. For example, many services that are established by a signaling protocol or other “real-time” media delivery protocols, e.g. Session Initiated Protocol (SiP), Real Time Streaming Protocol (RTSP), Real-time Transport Protocol (RTP), H.323, and Media Gateway Control Protocol (MGCP), dynamically assign port numbers for communication of the media application.